15116511661 has 2 divisors, whose sum is σ = 15116511662. Its totient is φ = 15116511660.

The previous prime is 15116511643. The next prime is 15116511691. The reversal of 15116511661 is 16611561151.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 12233466025 + 2883045636 = 110605^2 + 53694^2 .

It is an emirp because it is prime and its reverse (16611561151) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 15116511661 - 2²¹ = 15114414509 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (15116511691) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 7558255830 + 7558255831.

It is an arithmetic number, because the mean of its divisors is an integer number (7558255831).

Almost surely, 2^15116511661 is an apocalyptic number.

It is an amenable number.

15116511661 is a deficient number, since it is larger than the sum of its proper divisors (1).

15116511661 is an equidigital number, since it uses as much as digits as its factorization.

15116511661 is an evil number, because the sum of its binary digits is even.

The product of its digits is 5400, while the sum is 34.

The spelling of 15116511661 in words is "fifteen billion, one hundred sixteen million, five hundred eleven thousand, six hundred sixty-one".